Electric-arc lamp.



A. ZANOTTA.

ELECTRIC ARG LAMP.

APPLICATION FILED 00T. 31. 1914.

1,1 30,460, Patented Mar. 2, 1915.

par o e Ammiano zANo'rra, or mmm, ITALY.

ELECTRIC-ARC LAMP.

Specification of Letters Patent.

Patented Mar. 2, 1915.

Application filed October 31, 1914. Serial No. 869,657.

T 0 all whom it may concern Be it knowr. that I, ARMANDO ZANOTTA, av subject of the King of Italy, residing at Via Borgogna No. 8, Milan, in the Kingdom of Italy, have invented certain new and useful Improvements in Electric-Arc Lamps; and I do hereby declare the following to be a full, clear, and eXactdescription of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in electric arc lamps.

At present the lamps for cinematographic projections consist of a voltaic arc and the excess of tension, which normally existsthe tension of line generally havingI a value corresponding to about the triple of that necessary for the working of the arc-is absorbed through resistances and produces a useless wasting of energy, and, what is worse, a development of heat, which is the more harmful and dangerous being in the vicinity of substances very easily iniammable, as the cinematographic films.

One object of my invention is to produce a projecting lamp which shall comprise means to provide a plurality of arcs disposed in series, so that they will absorb themselves, without need of additional resistance, most of the tension on the line, and in this way, by smaller consumption of current, effect a greater luminous intensity, because a larger amount of the energy, instead of being uselessly absorbed by resistances, is transformed into light.

A'further object is to provide simple and eflicient means whereby the electrodes of the lamp may be quickly and accurately` adjusted with relation to each other and to the lens of the apparatus.

VViththese and other objects in view, the invention consists in certain novel features of construction and combination of parts as hereinafter set forth and pointed out in the claims.

The accompanying drawing is a view, partly in section and partly in elevation, showing an embodiment of 'my invention.

In the lamp shown in the drawing, carbons 33 and 34 are supported, respectively, by holders 35 and 36 carried by arms 37 and 38; the latter being carried by bars 39 and 40. The bars 39, 40, are guided in a support 41 and can be made to run longitudinally in reverse direction, so as to obtain the recession or the approach of the arms 37 and 38 and',l therefore, also of the cai-bons 33 and 34. This opposite movement of the bars 39 and 40 is produced by a pinion 42 gearing with racks 43 and 44 on the bars 39 and 40, and disposed in such a manner to be placed one at one side, and the other at the other side, of the pinion 42. This pinion carries a screw prolongation 45 which enters a threaded socket in an intermediate bar 46, the latter being guided in the support 41, and, to this intermediate bar, an "intermediate holder 47, for a carbon 48, is hinged. By working the pinion 42, by the aid of rod 49, the lowering or the elevations of the carbons 33 and 34 and the advancement or the retrocession of the carbon 48, are cotemporaneously caused; 'that is to say, the approach or the recession of the three carbons, one in respect to the others, may be effected.

The upper arm 38 is hollow and has such a form that the piece 51, which constitutes part of the carbon holder, 35, may be caused to run forward and backward by the rotation lof a threaded rod swiveled in the arm 38 and entering a threaded socket in said piece 51. By operating the rod 50 the carbon 33 may be caused to advance or to recede. Moreover, thev arm 38 is joined to the bar 40 so that it may turn with respect to the axis of the latter. Such a rotary movement may be transmitted to the arm 38 by means of a rod' 52 and bevel gearing 53 and 54. A rod 55, mounted in an arm a, carries a worm 56 meshing with said metal worm 57 made rigid with the holder 47 which carries the carbon 48. By operating the rod' 55 the carbon 48 may be angularly displaced lso as to approach more or less to one or the other of the carbons 33 and 34. Now by working the bars 50, 52 and 55, the positions of the carbons 33 and 48, in respect to the other carbon 34, may be respectively regulated. The regulation of the three carbons in respect to each other, is obtained by operating the rod 49.

The lamp may be adjusted laterally by a gear 60 engaging a rack Gl in the lamp frame, said gear being carried by a man ually operable shaft 59. Backward and for- Ward adjustment of the lamp may be effected by screws 65, and the lamp may be adjusted vertically by means of rack and pinion gearing (i3-G4 controlledlby a manually operable shaft 62. The lamp and its electrodes will, in all cases 'be adjustable with respect to the lens of the projecting apparatus, said lens being shown diagramniatically in the drawings at 66.

Having now particularly described and ascertained the nature of the saidV invention, and in what manner the same is to be per'- formed, I declare that whatI claim is:

1. In a projection apparatus, a lens, means for holding three electrodes so' as to 'converge toward the lens with one of the electrodes in substantial alinement with the axis of the lens, and means for' moving said latter electrode axially and the other two electrodes toward and away from it.

2. In a projector typeV arc lamp, a lens,

I means for holding three electrodes in sub- 5stantially the same plane, with the outer two holding three electrodes in substantially the same plane, with the outer two inclined with respect to the central electrode to cause the three toconverge toward a common point,

- manually operable -means for simultaneously 35 moving the outer two electrodes toward and away from 'the axis 'of the third or central electrode andfor moving the latter axially, respectively, toward and away from the point of convergence of the electrodes.

4. In a projection apparatus, a lens, means for holding three electrodes so as to converge toward the lens with one of the electrodes in substantial alinement with the axis of the lens, means for moving said latter electrode axially and the other two 'electrodes toward and 'away from it, including a support ex. tending substantially parallel to theaxis of the central electrode, a holder for one of saidelectrodes slidable on said support and manually operable means for moving said holder relative to said support.

5. In a projection apparatus, a lens, means for holding three electrodes so as to converge toward the lens with one of the electrodes in substantial alinement with theV axis of the lens, means for moving said latter electrode axially and the other two electrodes toward and away from it, land means for moving the end of one of the outer elec trodes toward or away from the plane defined by the ,axes of the other two electrodes.

6. In a projection apparatlus, a lens, means for holding three electrodes so as to converge toward the lens with one of the electrodes in substantial alinement with the axis of the lens, means for moving said latter electrode axially and the other two electrodes toward and away from it, including a support, overlapping bars, each provided with a rack, sliding in said support, electrode holders on said bars and a manually operable pinion coacting with said racks.

7.v In a projection apparatus, a lens, means for holding threeelectrodes so as to converge toward the lens with one of the electrodes in substantial alinement with the axis of the lens, means for moving said latter electrode axially and the other two electrodes toward and away from it, including a support, a holder for the central electrode slidable in saidy support anda manually operable screw for moving said holder relative to said support.

8. In a projection apparatus, a lens, means for holdingthree electrodes so as to converge toward thelens with one ofxthe electrodes in substantial alinement with the axis of the lens, means for moving said latter electrode axially and the other two electrodes toward and away from 1t, and means formoving the end of the central electrode toward the end ofone of the other electrodes and away from the end of the third electrode.

9. An arc lamp Jfor cinematographic projections, comprising supporting means, three electrode carriers, one being intermediate of the other two, electrodes mounted 1 n said carriers, the outer electrodes converging toward the central electrode whereby two separate arcs in series .may be formed simultaneously, adjusting devices for the in termediate carrier, whereby the intermediate electrode may be moved laterally relatively to the other-two, and means for laterally adjusting one of said other two electrodes.

10. An arc lamp for cinematographic projections, comprising supporting means, a

central electrode carrier, two lateral electrodecarriers, electrodes mounted in said carriers, the outer electrodes converging toward the central electrode whereby 'two separate arcs may be formed in series, means lfor adjusting the two lateral electrode carriers'toward or away from the central electrode carrier, and means for laterally ad.

justing the central carrier.

In testimony whereof, I ailix my signature, in presence of twowitnesses. j

ARMANDO ZANOTTA.

Witnesses: ARTHUR P. CORDEN,

.ANGELO CA'i'rANEsI. 

